In order to get a better idea of the mechanisms involved, I ordered and assembled a MeArm.  I must say, for the price it's unbelievable! Here are a couple of photos.

There are a few improvements I'd make.  One, I wouldn't try supporting the entire mass of the arm a tiny 9g servo.  I would try to support it on a bearing plate, or thrust washer or something similar.  It can even be a piece of plastic.  Two, actually there is no two!  It works well!

In order to start designing mine, I have begun to use the above 2D-lasercut parts as a "baseline" for my own arm.  I used to use Solidworks but now I'm trying to keep it all open-source including the design.  Thus, OpenSCAD.  I have posted the beginning of my SCAD code here:

https://github.com/jonnycowboy/armGen/blob/master/arm.scad

which will let you parametrically design any of the support arms above, in 2D.  You can then export a DXF for cutting directly.